[RFC] Screen Events API

[ENDERZOMBI102]

Proposal for a possible Screens Events API v0

• PRE: Start of openScreen, able to replace or undo the opening of a screen.
  Possible listener type:

  typealias OpenScreenEvent = ( client: Minecraft, screen: Screen? ) -> Screen?

• INIT: Called after a screen's own init() has been called, useful for adding widgets.
  Possible listener type:

  typealias InitScreenEvent = ( val client: Minecraft, val screen: Screen ) -> Unit

• TICK: Called after a screen's own tick() has been called.
  Possible listener type:

  typealias TickScreenEvent = ( val client: Minecraft, var screen: Screen ) -> Unit

• RENDER: Called after a screen's own render() has been called, useful to draw atop.
  Possible listener type:

  typealias RenderScreenEvent = ( val client: Minecraft, var screen: Screen, dt: Float ) -> Unit

• SCALE_CHANGE: Called after the scale of the UI has been changed.
  Possible listener type:

  typealias ScaleChangeEvent = ( val client: Minecraft, val old: Int, val current: Int ) -> Unit

• REMOVED: Called after a screen has been closed.
  Possible listener type:

  typealias RemovedScreenEvent = ( val client: Minecraft, var screen: Screen ) -> Unit

[SpaceWalkerRS]

I imagine the PRE event could eventually be handled through phases once the Events API gets the fancy treatment. Perhaps a RESIZE event could be useful as well? Or a combination of the two? A resize may or may not trigger a scale change so functionality for both could be useful.

[ENDERZOMBI102]

I imagine the PRE event could eventually be handled through phases once the Events API gets the fancy treatment.

Not exactly, they're different events with different guarantees, one presumes the screen has nothing be with and thus can be replaced safely, the other assures you that the screen's state is sound and can be depended on.